Advance and position indicator for coal-cutter or like stoping machine



3,220,01 1' CUTTER Nov. 23, 1965 G. FRAISSE ADVANCE AND POSITIONINDICATOR FOR COAL- OR LIKE STOPING MACHINE 2 Sheets-Sheet 1 Filed Oct.22, 1963 3,220,011 CUTTER G. FRAISSE Nov. 23, 1965 ADVANCE AND POSITIONINDICATOR FOR COAL OR LIKE STOPING MACHINE 2 Sheets-Sheet 2 Filed 001:.22. 1965 United States Patent 3,220,011 ADVANCE AND POSITION INDICATORFOR COAL-CUTTER 0R LIKE STOPING MACHINE George Fraisse, Petite-Rosselle,Moselle, France, as-

signor to Houilleres du Bassin dc Lorraine, Moselle, France Filed Oct.22, 1963, Ser. No. 317,885 Claims priority, application France, Oct. 23,1962, 913,120, Patent 1,361,864 4 Claims. (Cl. 346-33) This inventionrelates to indicator means adapted for being employed with coal cuttermachines or like stoping apparatus.

In mines, the progress made in operating methods depend upon theobtaining of accurate measurements. Thus, it became possible to developthe mechanization of mine workings by graphically establishing theworking cycles of coal-cutters or stoping machines, by manuallyplotting, subsequent to timing, the displacement times of thecoal-cutter. Such diagrams are complementary to the reports made by thesupervising personnel and furnish the higher staif level not only with asynthesized insight into the rate of advance of a cutting face but alsowith elements of comparison between in dividual stations or individualmine workings. It might be added that, generally speaking, such diagramsfacilitate work programming at a cutting face and enable the supervisingpersonnel to make a quantitative estimate of the magnitude of possibleincidents and an objective assessment of the effect of a poor operatingmethod, from one station to the other.

This manual method, however, has its limitations as well as numerousdrawbacks. The timing procedures are inevitably hasty and improvised tosome extent and are concerned only with the arrival and departure of thecoal-cutter at the ends of the cutting face and with importantincidents, such as those entailing stoppages of over five minutes. Thismethod, furthermore, leads to the timing operation being entrustedeither to the foreman at the cutting face, thereby further burdening histasks, or to a full-time time-study man, thereby increasing the laborstrength. To this can be added the inaccuracies and inadequaciesinherent in the method, which stem from the time-study mans aptitudesand behavior alike. Finally, the diagram is not obtained forthwith butmust be established a posteriori.

With a view to overcoming these inadequacies and drawbacks andautomatically recording the travel of the coal-cutter or stoping machinein terms of time at a point remote from the working and particularlyfrom the office of the engineer in charge of operating the coal face,the present invention has for its object to provide a rate-of-advancerecorder for a coal-cutter or like stoping machine with advance andposition indicator, characterized in that its comprises, on the onehand, an underground selective generator of electrical pulsescorresponding respectively to a determinate amount of travel of thecoal-cutter during its forward and reverse motions and, on the otherhand, a surface recorder having a drum which is rotated at uniform speedand associated with a stylus moved longitudinally of itself by a wormgear which is rotated step by step in one direction or the other by aselective pulse receiver.

Such advance and position indicator apparatus acts as an integrator ofelectrical pulses emitted at a frequency proportional to the speed ofthe coal-cutter, and enables the obtaining of a complete harmonogram ofthe rate of advance on the cutting face for twenty-four hours. Itenables all movement of the coal-cutter in the mine working to befollowed visually at all times Patented Nov. 23, 1965 'ice while agraphical representation of the work is obtained immediately, at thesame time. The apparatus also provides continuous, full and objectiveobservation of the rate of advance of the mechanized cutting faces andenables obtaining a solution to many problems which have hithertoremained obscure for lack of precise or systematic information.

The description which follows with reference to the accompanyingdrawings, which are filed by way of nonlimitative examples, will give aclear understanding of how the invention can be carried into practiceand will disclose still further particularities thereof.

Referring to the drawings filed herewith:

FIGURE 1 shows schematically the selective pulse generator of theindicator apparatus according to this invention;

FIGURE 2 shows in perspective the worm gear, the stylus, and therecording drum;

FIGURE 3 is an overall circuit diagram; and

FIGURE 4 shows a graph obtained with the indicator apparatus accordingto the present invention.

Referring first to FIGURE 1, the selective pulse generator shown thereoncomprises a cam 1 having lobes 2 mutually spaced at equal angulardistances. Said cam is mounted concentrically on a driving sprocketwheel 3 of the winch that meshes with the chain 4 stretched along thelength of the conveyor and enables the machine to be displaced. As thewhole assembly rotates, the lobes 2 of cam 1 coact with one of the ends5 of a lever 6 which is fulcrumed about a vertical shaft 7 and the otherend 8 of which is adapted to actuate one of two .pushbuttons or selectorcontacts 9 9,. The shape of the end 5 of lever 6 is so determined thateach lobe 2 causes said lever to tilt towards that pushbutton whichcorresponds to the direction of travel of the coal-cutter and at thesame time permits escapement of that particular lobe with respect to thelever end. If the coal-cutter moves in the direction of arrow P in thecoal-cutting process and in the direction of arrow F during the returnphase, then selector contact 9,. will sustain the pressures of lever 6during the return phase, as shown in the figure, whereas selectorcontact 9 will sustain the pressures of lever 6 during the coal-cuttingphase. This assembly could be disposed underneath the standardprotective enclosure provided for the bosses.

The electrical pulses generated by the successive pressures of lever 6on one of selector contacts 9 9, for a specific work phase and thenumber of which is proportional to the distance travelled by thecoal-cutter, are conveyed up to the surface by a telephone network 11(FIGURE 3) and reach the indicator proper. The latter consists of a drum12 rotated uniformly about its shaft by a clockwork mechanism (notshown), whereby to furnish a time scale. Said drum is provided with agraph-paper support 13 upon which bears a stylus 14 rigid with a nut 15cooperating with an endless screw 16 in such manner as to be translatedby rotation of said screw. Each electrical pulse delivered by thecoalcutter energizes an electrical actuating relay 17, or 17,- whichcauses the endless screw to rotate in response to the thrust of a pawl18,, or 18 against one of two op positely toothed ratchet wheels 19 19supported by said endless screw, whereby to rotate the latter by afraction of a revolution that is function of the number of teeth onratchet Wheels 19 and 19,. Thus, displacement of nut 15 faithfullyfollows the advance of the machine, while motion of the stylus 14 on thegraph support 13, which stems from the composition of the motion of nut15 and the rotation of drum 12, enables the space-time graph of themotion of the coal-cutter to be obtained.

In order to enable the pulses to be transmitted from the coal-cutter tothe indicator, a junction box 2% is connected past the selector contacts9 and 9 This box comprises a rectifier Ell interposed between one of thepoles 22 of a source S of low-voltage (24 volts, say) electric currentand one of the fixed contact studs of the selec tor contacts. The otherpole 23 of said source is con nected to each of the other fixed contactstuds of selector contacts 9, and fi via servo-control relays 2 t and24-, which, when energized, are adapted to close two normallyopencontacts 25 and 25,. One of the fixed contact studs of said contacts isconnected through a rectifier 25 to one of the poles of a secondlow-voltage source of electric current, while their other studs areconnected to the other pole of the latter-mentioned source, as will bedescribed hereinafter. The assembly 27, consisting of relays M 24,,rectifier 26, and contacts 25 25,, forms a servocontrol box for thedirection of travel of the coal-cutter. The source S, the relays 24 2d,,the rectifier 21 and the selector contacts 9 9 form an intrinsic safetycircuit.

The second source of low-voltage current consists of a transformer theprimary winding 28 of which is connected, for example, to a 220 v. gridand the secondary winding 29 of which delivers 24 v. for example. One ofthe extremities of the secondary winding is on the one hand groundedthrough fuse 30 and, on the other, connected to rectifier 26 as well asto one of the studs of two normallyopen contacts 31 and 31,. of controlrelays 32,, and 32,. The other extremity of secondary winding 29 isconnected via control relays 32 and 32 to the other studs of contacts 25and 25,. It additionally supplies the actuating relays 17 and 17 whichare connected to the other studs of contacts 31 and 31, through normallyclosed limit contacts 33 33, and normally-closed locking contacts 3% and34,.

The apparatus hereinbefore described functions in the following manner:

If the coal-cutter is considered during the return or loading phase,selector contact 9 is closed, thereby energizing servo-control relay 2d,and closing its contact 25,. The servo-control box 27 does then indeedfulfill its function, since it servo-controls the whole to the returnchannel. On closure of contact 25,, control relay 32,. is energized,thereby simultaneously closing its contact 3l and opening lockingcontact 34 whereby to ensure that only actuating relay 17 is energized.The pawl 1d then drivingly engages with ratchet wheel 1% to move the nut15 in the direction of arrow f (see FIGURES 2 and 3). When it reachesthe end of its return path, the nut operates on limit contact 33,,thereby deenergizing relay 17,.

In one possible embodiment, cam it has four lobes, while drivingsprocket 3 has seven cogs and meshes with a marine-type chain having apitch of 0.128 metre; each pulse consequently corresponds to adisplacement of the coal-cutter through 0.224 metre. Each ratchet wheel19 has twelve teeth, the scale chosen for the graph is one millimetreper metre and one millimetre for two minutes, which means that theendless screw 16 will have a pitch of 2.688 mm.

FIGURE 4 shows one of the graphs obtained with the apparatushereinbefore specified. This graph provides instant detection of allincidents occurring during operation of the coal-cutter. Thus it may beseen that during the first coal-cutting and return phase, at a a largeblock has become jammed during the outfall, at b a slow-down has beenintroduced by an overhang, at c the precutting arm has become jammed, atd the stop at the loading point has occurred followed by an overhangblasting, at e and at f the machine has been raised for cleaning priorto scraping, following which scraping was effected at g. During thesecond cutting and return phase, at h the drum became jammed in theface, at i the machine was halted because of an overhang, at j theoverhang was blasted and the timbering transported and at k the scrapingand timbering were carried out. During the third cutting and returnphase, at I there was a change of crew, at m a halt for haulage and at nscraping and timbering. Lastly, during the fourth cutting and returnphase, at 0 the precutting arm became jammed, at p several falls from anoverhang caused numerous jammings of the machine, while at q theoverhang fell. There was no material to convey over the return path.

Such an indicator now makes it possible, in mining operations, toimmediately determine a theoretical cycle of maximum daily advance for agiven material and seam, thereby permitting optimum programming of thetimbering or stowing cycles. It additionally enables coal-cutter picksto be evaluated and the optimum frequency of their replacement to bedetermined. Similarly, to achieve an integral coal-cutting operation,the recording of a series of tests will bring out, through a comparativestudy of the graphs, the most advantageous characteristics, from thestandpoints for instance of length, depthwise position, and number ofheads on the precutting arm which is mounted on the stoping machine,more particularly for breaking up dangerous overhangs that might remainattached to the roof subsequent to passage of the principal drum.Lastly, it is also possible to observe the behavior of the loading shoesin terms of evacuation of the fines, to detect the hard zones and notethe effect of concussion blasts or of injecting water into the mass, andfinally to note what difficulties are encountered in handling thematerial in the mine working as a function of the seam openings.

In addition to starting and end-of-station times, the apparatus enablesall stoppages of the coal-cutter or the stoping machine to be recorded.Thus, for example, if the subject apparatus of the present invention iscombined with a conveyor travel recorder, it can be established to whatextent the work which has been or is to be carried out at a cutting faceis governed by the haulage effected by the conveyor. Finally, thisinvention enables repetitive incidents at a cutting face to be detectedand the lay-up times to be thereby reduced by precise and continuousmonitoring.

What I claim is:

l. An advance and position indicator for coal-cutters of the type havinga winch provided with a driving sprocket wheel which, for displacing thecoal cutter, engages a stationary chain disposed along the length of anassociated conveyor to be loaded by the coal-cutter, said recordercomprising a source of current at ground level, two normally openunderground selector contacts connected to said source, means connectedto the driving sprocket wheel of the coal-cutter for closing arespective one of said contacts for a determinate displacement of thecoal-cutter during opposite strokes thereof corresponding to cutting andreturn motion, to generate selective electrical pulses, means forconveying said pulses to ground level, a recorder at ground levelincluding a rotary drum with an axis and a stylus at right angles to theaxis of said drum and displaceable parallel to said axis, means forrotating said drum at uniform speed, means for step by step displacingsaid stylus parallel to said axis in opposite directions, and selectivepulse receiving means interconnecting the conveying means and the stepby step displacing means for controlling the displacement of said stylusin relation to those of said coal-cutter during its cutting and returnmotion, respectively, said means for the step by step displacing of thestylus comprising a nut rigid with the stylus, an endless screw parallelto the drum axis and engaging said nut, and means interconnecting saidselective pulse receiving means and said endless screw for rotating saidscrew step by step in respective opposite directions, the latter meanscomprising two oppositely toothed ratchet wheels respectively mounted onthe extremities of said screw, two actuating relays connected to theselective pulse receiving means respectively energized by the pulsesgenerated during the cutting and return motion of the coal-cutter, andtwo pawls respectively controlled by said relays for respectivelyengaging said ratchet wheels, said selective pulse receiving meanscomprising a second source of current one pole of which is connected toone end of the actuating relays, two control relays interconnecting saidone pole of said second source and the means for conveying the pulses,said control relays having normally open contacts connected to the otherpole of said second source, two normally closed limit contactsrespectively connected to the other end of said actuating relays andadapted to be opened by the nut when said nut reaches the ends of itspath, and two normally closed locking contacts respectivelyinterconnecting said limit contacts and the contacts of said controlrelays, each one of said locking contacts being opened when the controlrelay the contact of which is not connected to it is energized.

2. An indicator according to claim 1, wherein the second source ofcurrent comprises the secondary winding of a transformer having aprimary winding which is connected to a grid.

3. An indicator according to claim 1, wherein the means for conveyingthe pulses to ground level comprises a telephone link connecting thecontrol relays of the surface selective pulse receiving means and theunderground selector contacts.

4. An indicator according to claim 1, wherein the telephone linkcomprises a junction box having a rectifier in terconnecting one pole ofthe first source of current and the selector contacts, and adirection-of-travel servo-control box comprising two servo-controlrelays respectively interconnecting the other pole of said first sourceof current and the selector contacts and the contacts of which arenormally open and connected to the control relays of the selective pulsereceiving means, and a second rectifier interconnecting the other poleof the second source of current and the contacts of said servo-controlrelays.

References Cited by the Examiner UNITED STATES PATENTS 880,592 3/1908Sterling 34633 938,516 11/1909 Russell 346-138 X 2,326,219 8/1943Hayward 346-33 X 2,390,178 12/1945 Rutherford 34630 2,628,498 2/1953Smith. 3,009,355 11/1961 Abs et al. 346-33 X LEO SMILOW, PrimaryExaminer.

1. AN ADVANCE AND POSITION INDICATOR FOR COAL-CUTTERS OF THE TYPE HAVINGA WINCH PROVIDED WITH A DRIVING SPROCKET WHEEL WHICH, FOR DISPLACING THECOAL CUTTER, ENGAGES A STATIONARY CHAIN DISPOSED ALONG THE LENGTH OF ANASSOCIATED CONVEYOR TO BE LOADED BY THE COAL-CUTTER, SAID RECORDERCOMPRISING A SOURCE OF CURRENT AT GROUND LEVEL, TWO NORMALLY OPENUNDERGROUND SELECTOR CONTACTS CONNECTED TO SAID SOURCE, MEANS CONNECTEDTO THE DRIVING SPROCKET WHEEL OF THE COAL-CUTTER FOR CLOSING ARESPECTIVE ONE OF SAID CONTACTS FOR A DETERMINATE DISPLACEMENT OF THECOAL-CUTTER DURING OPPOSITE STROKES THEREOF CORRESPONDING TO CUTTING ANDRETURN MOTION, TO GENERATE SELECTIVE ELECTRICAL PULSES, MEANS FORCONVEYING SAID PULSES TO GROUND LEVEL, A RECORDER AT GROUND LEVELINCLUDING A ROTARY DRUM WITH AN AXIS AND A STYLUS AT RIGHT ANGLES TO THEAXIS OF SAID DRUM AND DISPLACEABLE PARALLEL TO SAID AXIS, MEANS FORROTATING SAID DRUM AT UNIFORM SPEED, MEANS FOR STEP BY STEP DISPLACINGSAID STYLUS PARALLEL TO SAID AXIS IN OPPOSITE DIRECTIONS, AND SELECTIVEPULSE RECEIVING MEANS INTERCONNECTING THE CONVEYING MEANS AND THE STEPBY STEP DISPLACING MEANS FOR CONTROLLING THE DISPLACEMENT OF SAID STYLUSIN RELATION TO THOSE OF SAID COAL-CUTTER DURING ITS CUTTING AND RETURNMOTION, RESPECTIVELY, SAID MEANS FOR THE STEP BY STEP DISPLACING OF THESTYLUS COMPRISING A NUT RIGID WITH THE STYLUS, AN ENDLESS SCREW PARALLELTO THE DRUM AXIS AND ENGAGING SAID NUT, AND MEANS INTERCONNECTING SAIDSELECTIVE PULSE RECEIVING MEANS AND SAID ENDLESS SCREW FOR ROTATING SAIDSCREW STEP BY STEP IN RESPECTIVE OPPOSITE DIRECTIONS, THE LATTER MEANSCOMPRISING TWO OPPOSITELY TOOTHED RATCHET WHEELS RESPECTIVELY MOUNTED ONTHE EXTREMITIES OF SAID SCREW, TWO ACTUATING RELAYS CONNECTED TO THESELECTIVE PULSE RECEIVING MEANS RESPECTIVELY ENERGIZED BY THE PULSESGENERATED DURING THE CUTTING AND RETURN MOTION OF THE COAL-CUTTER, ANDTWO PAWLS RESPECTIVELY CONTROLLED BY SAID RELAYS FOR RESPECTIVELYENGAGING SAID RATCHET WHEELS, SAID SELECTIVE PULSE RECEIVING MEANSCOMPRISING A SECOND SOURCE OF CURRENT ONE POLE OF WHICH IS CONNECTED TOONE END OF THE ACTUATING RELAYS, TWO CONTROL RELAYS INTERCONNECTING SAIDONE POLE OF SAID SECOND SOURCE AND THE MEANS FOR CONVEYING THE PULSES,SAID CONTROL RELAYS HAVING NORMALLY OPEN CONTACTS CONNECTED TO THE OTHERPOLE OF SAID SECOND SOURCE, TWO NORMALLY CLOSED LIMIT CONTACTSRESPECTIVELY CONNECTED TO THE OTHER END OF SAID ACTUATING RELAYS ANDADAPTED TO BE OPENED BY THE NUT WHEN SAID NUT REACHES THE ENDS OF ITSPATH, AND TWO NORMALLY CLOSED LOCKING CONTACTS RESPECTIVELYINTERCONNECTING SAID LIMIT CONTACTS AND THE CONTACTS OF SAID CONTROLRELAYS, EACH ONE OF SAID LOCKING CONTACTS BEING OPENED WHEN THE CONTROLRELAY THE CONTACT OF WHICH IS NOT CONNECTED TO IT IS ENERGIZED.